Tobacco-Containing Consumable For Aerosol Generating Devices

ABSTRACT

A non-combustible tobacco article for use in conjunction with a heat source to produce an inhalable aerosol includes at least one tobacco derived portion, at least one distal filter portion and at least one mouth-end filter portion held together in an overwrap; the complete article having a compressibility factor in the longitudinal axis of &lt;10%.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a national phase entry under 35 U.S.C. § 371of International Application No. PCT/GB2018/051416, filed May 24, 2018,published in English, which claims priority to Great Britain PatentApplication No. 1708331.2, filed May 24, 2017, the disclosures of whichare incorporated herein by reference.

BACKGROUND OF THE INVENTION

Many alternatives to traditional combustible tobacco products have beenlaunched in recent years.

Electronic Cigarettes use battery power to heat a nicotine-containingaerosol-generating liquid to form an inhalable nicotine-containingaerosol. Such products tend not to contain tobacco.

Heated Tobacco Products use various energy sources and means to heat atobacco-containing consumable to generate an inhalable aerosol thatcontains some components derived from tobacco, including flavour andnicotine.

There are also various “hybrid” products which can combine technologyfrom both electronic cigarettes and Heated Tobacco Products in order togenerate an inhalable nicotine-containing aerosol wherein flavour andnicotine can originate from either the aerosol-generating liquid or thetobacco portions.

Specific examples of existing technologies include:

WO9639880 and WO2013190036 describe a cigarette-like cylindricalconsumable article, with a distal end containing tobacco-derivedmaterial, typically crimped reconstituted tobacco sheet, a mouth-endfilter typically containing multiple segments, and an overwrap made frompaper. Said article is intended to be electrically heated in order toproduce an inhalable nicotine-containing aerosol.

WO2016207407 also describes a tobacco consumable intended forconsumption by heating, namely a distal tobacco-derived portion, amouth-end filter and a paper overwrap.

US2009151717 describes a small metallic capsule (“pod”) with a foil lidthat is pierced prior to use. Inside the pod, the tobacco-derivedmaterial typically comprises finely ground tobacco particles, humectantsand flavourings.

WO2016159013 describes a device in which an aerosol is generated byheating a liquid which is then passed through a separate tobaccoportion; the tobacco portion imparts flavour and/or nicotine to thefinal aerosol. The tobacco portion can be held within a moulded plasticcapsule with a mesh at the distal end and a small filter at themouth-end.

WO2016135342 describes a product which operates in a similar manner tothat described in WO2016159013, however the tobacco portion and theliquid heating unit are comprised as one unit. The tobacco portion isheld within a moulded plastic structure with a filter at the mouth-end.

With regards to the consumable units for these products, there are somerecognised limitations.

For example, with consumables manufactured using cigarette-rod-makingtechnology the user can mistakenly ignite the consumable and potentiallyinhale unintended and or undesirable combustion products. Also,consumables utilising plastic or metal capsules require bespokemanufacturing machinery, have limited environmental recyclability, andhave high material & manufacturing costs.

BRIEF SUMMARY OF THE INVENTION

The current invention describes a tobacco-containing consumable articlefor use in aerosol-generating devices comprising at least atobacco-derived portion, a distal filter portion and a mouth-end filterportion held together in a continuous overwrap, with a compressibilityfactor less than 10%.

The article may have a total pressure drop <120 mm water column alongits longitudinal axis. The pressure drop is preferably in the range of 5to 40 mm water column and more preferably is in the range 10 to 30 mmwater column. Such a consumable may be manufactured using conventionalcavity-filter-making technology, well known within the tobacco industryand shown in U.S. Pat. No. 6,537,186 for example. In such prior artarrangements, a filter is manufactured with a distal filter portion, acavity to receive typically a solid granular material such as activatedcarbon, and a mouth-end filter portion all held together by a paperoverwrap. Products have also existed which utilised tobacco-derivedmaterial within said cavity to impart or attenuate flavour to the smokeas it passes through the filter.

The current invention therefore allows production of consumables viareadily-available high-speed production machinery, using provenmanufacturing technology, with low material and production costs,material & design flexibility, and can be compatible with a variety ofaerosol-generating systems.

In some examples, the article may modify one or more other organolepticproperties of the aerosol (e.g. modifying the feel or smell or look ofthe aerosol to the user).

In some examples, the article may comprise a substance that modifies thePH of the aerosol by either lowering or raising the PH (e.g. modifyingthe acidity or the basicity of the aerosol).

In some examples, the article may modify (e.g. reduce) the amount ofaldehydes in the aerosol.

As described herein, a non-combustible tobacco article means an articlecontaining a tobacco-derived portion that is not intended to becombusted as a whole or in part during use, and no part of said articleis intended to be lit during use. Furthermore the construction of saidarticle resists ignition through the use of filter materials such ascellulose acetate at both the distal and mouth ends.

The term aerosol shall be interpreted to include gas, vapour, droplets,condensates, particulates and combinations thereof. An inhalable aerosolshall mean an aerosol with an average particle size as measured by laserdispersion ranging from 0.1 to 10 μm, more preferably 0.1 to 1.5 μm.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of the present invention will now be described with referenceto the accompanying drawings, in which:

FIG. 1 is a side schematic view of an article according to theinvention;

FIG. 2 is a side schematic view of an article according to the inventionshowing the longitudinal axis;

FIG. 3 is a side perspective view of an example filter portion andoverwrap for use in the invention employing multiple layers in itsoverwrap;

FIGS. 4, 5 and 6 are side schematic views of example articles accordingto the invention with different overwrap configurations;

FIGS. 7 and 8 are schematic views of a device employed in combinationwith the article of the invention;

FIG. 9 shows an example filter portion that can be employed in thearticle of the invention; and

FIG. 10 is a schematic view of an alternative method of employing thearticle of the invention to generate vapour.

DETAILED DESCRIPTION

FIG. 1 depicts the basic construction of the article of the invention.The mouth end 3 is the end of the article intended as the exit of theaerosol towards the user. The distal end 1 is the opposite end of thearticle, typically intended as the inlet for air and other materialsinto the article. A tobacco portion sits there between. By way ofexample, the length of the tobacco portion 2 is in the range 7 mm to 17mm and preferably in the range 10 mm to 13 mm, the length of each of thefilter portions 1,3 is in the range 3 mm to 15 mm and preferably in therange 4 mm to 6 mm and the diameter of the flavour container is in therange 5 mm to 8.5 mm. The dimensions depend upon a combination of theneed to provide sufficient material within the tobacco portion 2 toprovide a desired flavour effect whilst ensuring a balance between thethree sections overall to provide an appropriate pressure drop whilstretaining overall product strength and compressibility.

In the example of FIG. 1 part 2 is a tobacco-derived portion, which caninclude single-grade tobacco, blended tobacco grades, leaf, stem, dust,reconstituted tobacco, washed tobacco, extracted tobacco, treatedtobacco, tobacco extracts and mixtures thereof. The tobacco-derivedportion 2 can be produced from tobacco plants by methods includingharvesting, drying, cutting, shredding, grinding, extraction,reconstitution, extrusion and combinations thereof. The tobacco-derivedportion 2 can be present in the physical form of leaf, stem, dust,reconstituted sheet, crimped, folded, shaped, beaded, granulated andmixtures thereof. In most examples the tobacco portion 2 comprisestobacco although other botanicals or flavour agents may also be used. Invariations of the examples shown, the tobacco portion 2 may be occupiedby a cut tobacco rod or fully or partially by ground tobacco. Selectionof the material for the tobacco portion 2 is dependent upon a number offactors such as desired level of flavour delivery and the requirementsto meet an appropriate pressure drop.

In a preferred embodiment of this invention, the tobacco derived portion2 is obtained by carefully selecting a mix of cured tobacco grades basedupon desirable taste attributes and low levels of undesirable chemicals;reducing the particle size of the plant material by cutting or grindingto a size suitable for further processing; treating the tobacco materialto further reduce undesirable components via a suitable combination ofprocesses including liquid extraction, heat treatment, pressuretreatment and chemical treatment; adding ingredients includinghumectants to produce aerosol and flavourants; reconstituting thetobacco into a sheet format; drying to produce a stable material whichis added to the tobacco article either intact as crimped sheet or asfragments of cut or shredded sheet. The above steps can be interchanged,although size reduction is best formed at an early stage in the processand extraction is preferable before addition of flavours to minimiselosses of the added flavours. Drying is normally the final stage,although flavour/humectants can be added at the end.

In some examples a tobacco cut rag is used in the tobacco portion 2 inwhich case the density of the tobacco cut rag may be in the range of150-500 mg per cm3, preferably in the range 180-280 mg per cm3, and mostpreferably in the range 200-250 mg per cm3. Control of this size ensuresprovision of the maximum possible tobacco quantity within the volume ofthe tobacco portion 2 so that there is maximum transfer into theaerosol.

In a some examples, the tobacco portion 2 comprises a flavour materialthat has been ground or otherwise treated or formed so that it is in theform of particles, for example, powder, granules, grains, fibres, beads,pellets or the like so as, for example, to increase the active surfacearea or amount of the flavour material in order to maximise the amountof flavour imparted to a vapour and/or aerosol stream flowing throughthe article.

As used herein, the terms “flavour” and “flavourant” may refer tomaterials which, where local regulations permit, may be used to create adesired taste or aroma in a product for adult consumers. They mayinclude extracts (e.g., licorice, hydrangea, Japanese white barkmagnolia leaf, chamomile, fenugreek, clove, menthol, Japanese mint,aniseed, cinnamon, herb, wintergreen, cherry, berry, peach, apple,Drambuie, bourbon, scotch, whiskey, spearmint, peppermint, lavender,cardamom, celery, cascarilla, nutmeg, sandalwood, bergamot, geranium,honey essence, rose oil, vanilla, lemon oil, orange oil, cassia,caraway, cognac, jasmine, ylang-ylang, sage, fennel, piment, ginger,anise, coriander, coffee, or a mint oil from any species of the genusMentha), flavour enhancers, bitterness receptor site blockers, sensorialreceptor site activators or stimulators, sugars and/or sugar substitutes(e.g., sucralose, acesulfame potassium, aspartame, saccharine,cyclamates, lactose, sucrose, glucose, fructose, sorbitol, or mannitol),and other additives such as charcoal, chlorophyll, minerals, botanicals,or breath freshening agents. They may be imitation, synthetic or naturalingredients or blends thereof. They may be in any suitable form, forexample, oil, liquid, solid, or powder. For example, a liquid, oil, orother such fluid flavourant may be impregnated in a porous solidmaterial so as to impart flavour and/or other properties to that poroussolid material. As such, the liquid or oil is a constituent of thematerial in which it is impregnated.

To prevent excessive pressure drop it is preferable to have the majoraxis of the tobacco derived sheet running parallel to the longitudinalaxis 6 of the article of the invention to form pathways for air to pass(see FIG. 2, part 2). In an alternate preferred embodiment of thisinvention, the tobacco derived material is prepared as above except thatthe tobacco derived material is reconstituted into a granular orparticulate format which can then be added to the invention.

Preferably the granular or particulate tobacco derived material isproduced by extrusion, because this ensures consistency of particle sizeand shape as well as ensuring uniform distribution of any addedflavourant or humectant.

In the specific case of the material of the tobacco portion 2 comprisinga continuous fibre ground tobacco the tobacco weight is preferably inthe range of 2 mg to 6 mg per mm of the tobacco portion.

In the specific case of the material of the tobacco portion 2 comprisingshort cut fibres ground tobacco the tobacco weight is preferably in therange of 6 mg to 15 mg per mm of the tobacco portion 2.

FIG. 2 shows the longitudinal axis 6 of the article of the invention,taken as the major axis of the article and running from the mouth end 3to the distal end 1. Other axes are taken as perpendicular to thislongitudinal axis. Definition of such axes is important in themeasurement of key physical parameters that control the integrity of theproduct during storage & use, and of the sensory experience that theuser receives.

“Pressure drop” or “draw resistance” is measured using the CorestaRecommended Method 41.(https://www.coresta.org/sites/default/files/technical_documents/main/CRM_41-update2_0.pdf)and expressed as millimetres water-column equivalent. This designfeature determines how the user can extract a volume of aerosol from theconsumable/device with reasonable effort.

“Compressibility” is measured in the longitudinal axis 6 by applicationof a fixed force of 10 Newtons at points 5 (see FIG. 2), and measuringthe deflection distance as a percentage of the total product length.Such measurement can be performed using equipment such as Instron'selectromechanical rig 3300.

In FIG. 1 part 4 shows an “overwrap”: one or more sheets of materialthat provide the outer surface of the article, act to hold the separateelements (distal end filter 1, tobacco derived portion 2 and mouth-endfilter 3) in sequence relative to each other and provides structuralstrength to the article sufficient for required manipulation by theuser, in particular during insertion and removal from an associateddevice. An overwrap 4 typically comprises paper, plastic, foil,laminates or combinations thereof. An overwrap 4 can comprise a singlelayer over the entirety of the article or can have multiple layers atdifferent points as shown in FIG. 3, parts 8 and 9, as may be requireddepending on the underlying construction of the article, for examplemulti-segment filter portions are typically held together with an outerwrapper to assist manufacturing processes. Overwraps of particularrelevance to this invention preferably have grammage in the range of20-100 grams per square meter (gsm). A preferred embodiment utilises arigid non-porous overwrap in the range of 40-200 g/m² composed oftransparent cellulose-based paper without chalk overprinted withmetallic inks. The lower limit of the grammage is usually determined bythe need for opacity and physical strength for the end consumable. Theupper limit of the grammage range is set by the operability of themachinery, which can perform if the overwrap material is too thick. Interms of the preferred embodiment, an employment of a rigid non-porousoverwrap without chalk, this had advantages in that printing can beperformed on specific areas to provide shaped windows, logos etc.

In some examples, the overwrap 4 is configured so that its acts as aliquid resistant barrier that prevents liquid, for example, condensationthat forms around the article when it is in use, from getting into theinterior of the article and making the tobacco portion 2 soggy. In oneexample, a liquid resistance wrapper layer is used in the overwrap 4comprises paper impregnated with a barrier material or Natureflex orother suitable thin polymer film.

In a preferred embodiment of the present invention, the overwrap 4 issupplied as a continuous roll of material which is bent in thecross-direction, shaped into a continuous cylinder and affixed to itselfusing glue. Concurrent with the formation of this continuous cylinder ofoverwrap the internal elements, namely filter portions 1,3 and tobaccoderived portions 2, are supplied and affixed to the overwrap 4 asappropriate. This continuous cylinder is then cut into the discreettobacco articles. This process can be carried out in a continuous mannerusing a machine for producing cavity filters as known in the art. In analternative preferred embodiment, the continuous roll of overwrap isformed into a helix and affixed to itself to form the continuouscylindrical shape with a resultant spiral seam (as seen in FIG. 4). Ahelical arrangement has the further advantage that the seam can providefurther structural rigidity to the complete article by preventingcompression in the cross-direction.

FIGS. 4, 5 and 6 show exemplary embodiments wherein regions 11 aretransparent, and regions 12 are opaque. Transparent overwrap is definedby the ability to allow the user to visually perceive the contentsinside the article. Suitable properties can be found with transparent,semi-opaque and translucent materials. Accordingly regions oftransparency can be created within an overwrap 4 by altering thecomposition of the overwrap 4 in that region by means including reducingthe amount of print, reducing the amount of an opaque layer, removal ofa foil layer or combinations thereof. A preferred embodiment utilises atransparent cellulose-based paper opacified with metallic inks to give afoil-like appearance overall, and has regions with no metallic ink thatserve as transparent windows 11 to view the contents inside the article.Most preferably these transparent windows 11 are aligned with thetobacco derived portion 2.

During storage and use the physical properties of the overwrap 4 can beaffected by absorption of volatile, liquid and aerosol components. Forexample, paper based overwraps can absorb moisture and other liquidswhich soften the overwrap reducing its structural integrity; this can beundesirable as it can affect the user's ability to remove the articlefrom the associated device. It can also have a detrimental effect uponthe visual aesthetics of the overwrap, for example causing staining.Hence it is desirable to provide overwraps that resist the absorptionand therefore retain desirable structural properties and appearance. Toresist absorption overwraps can be composed of plastics and foils; havea plastic or foil inner layer; have an inner surface coated with varnishor lacquer; be composed of paper with low propensity to absorb liquidsand combinations thereof. These may include trilaminate foils with aPE:Al:PET type construction. In a preferred embodiment, the overwrap istransparent cellulose-based paper without chalk which exhibits a lowabsorption propensity. An alternate preferred embodiment the overwrap 4is a transparent film of plastic. An alternate preferred embodiment theoverwrap 4 is a paper based material coated with a layer of alkyl ketenedimer (AKD) on the inner surface.

Filter portions (FIG. 1, parts 1 and 3) act as a physical barrier tocontain the tobacco-derived portion 2 and maintain the overallstructural integrity of the tobacco article predominantly in the minoraxis whilst allowing the desired air and aerosol to pass through. Insome examples, the material of the filter is moisture resistant so thatthe filter portions 1,3 maintain their shape in use. The mouth-endfilter portion 3 can in addition act to prevent undesirable fine dustparticles from the tobacco derived portion 2 reaching the user andremoves aerosol particles larger than those of an inhalable aerosol.

The filter portions 1, 3 can each be provided by a filter portion 21. Toenhance airflow through the invention, the pressure drop of the filterportions 21 (shown in FIG. 9), can be reduced by the introduction of oneor more airflow channels 22 in the longitudinal axis. Airflow channels22 can pass the entire length of the filter portion. Preferably airflowchannels 22 pass through up to 95% of the filter portion length, leavingat least 5% of the filter portion intact to retain tobacco particles.Airflow channels 22 can be introduced once the filter portion 21 isformed by using lasers to burn through the filter material or by use ofa mechanical pin to punch the channel 22. Preferably airflow channels 22are formed by introducing a mandrel or pin into the filter materialduring the formation process to shape the channel.

In some examples, the pressure difference across either of the portions1,3 is in the range 0.1 mm to 2 mm water column per mm length of thesection.

Filter portions 21 typically are composed of cellulose acetate, paper,plastics, polymers such as polyethylene, polypropylene or polylacticacid and combinations thereof. In a preferred embodiment of the presentinvention the filter portion 21 is composed of cellulose acetate fibresplasticised with up to 15% triacetin. Filter portions 21 may behomogenous or composed of multiple contiguous segments. Filter portions21, and more preferably the mouth-end filter portion 3, can containattenuants, flavourants and aesthetic elements.

A different additional flavour component may be placed in each of theend filter portions 1,3 (e.g. a flavour capsule in distal portion 1 anda flavoured thread or line in the mouth portion 1).

In some examples, the filter portions 1,3 comprise a fibrous materialand may be, for example, a fibrous material that is typically used as afilter material in traditional cigarette, examples including celluloseacetate fibres, polypropylene fibres, polyster fibres and paper,including crimped paper. Other materials may be used for example, nylonand the like.

In another example, the material of the tobacco portion 2 and thematerial in the two filter portions 1,3 comprises a multiplicity ofshort cut CA fibres (for example fibres cut using a so called Turmalinapparatus) randomly orientated. Short cut CA fibres with for exampleground tobacco in tobacco portion 2, may use just enough of the fibresto hold the ground tobacco in a rod form. Benefits of this arrangementallow for a lower pressure drop of vapour and/or aerosol flow andadditionally there is reduced or no need for a plasticiser, for example,triacetine to hold the rod form as is required for a continuous fibreCA. Furthermore, use of short cut CA fibres enables the use of less CAand more tobacco than in the case of using a long continuous CA fibre.

In some examples, the percentage weight of first flavour component (andany other components e.g. charcoal, plasticiser) in the filter portions1,3 to the weight of the material of the tobacco portion 2 is in therange 10% to 90% and preferably in the range 70% to 90%.

In the specific case of the article comprising a continuous fibre andthe tobacco portion 2 comprising ground tobacco the tobacco weight tothe fibre weight is preferably in the range of 40% to 60% and mostpreferably in the range of 45% to 55%. The fibre weight is preferably inthe range of 75% to 95% and most preferably in the range of 80% to 90%.

Attenuants remove undesirable chemicals from the aerosol and includesolid particles of carbon, activated charcoal, carbonaceous resinderived by pyrolysis, silica, chemically activated derivatives of carbonand silica, metal based catalysts and mixtures thereof.

Flavourants add desirable sensory properties to the aerosol and can bepresent in the tobacco-derived portion, the filter portions andcombinations thereof. Common flavourants include menthol, mint,peppermint, vanilla, liquorice, fruit extracts, esters, acetals,fructals and combinations thereof. Flavourants can be present within thefilter matrix, the tobacco-derived material, in a flavour thread, inbeads, breakable capsules, non-breakable capsules, encapsulated within aprotective matrix, encapsulated within a molecule including cyclodextrinand combinations thereof.

Aesthetic elements include colourants dispersed within the filter matrixor localised within a specific region and filters shaped to form adistinct pattern, logo, or are recessed or fluted or is combinationthereof. This is represented in FIG. 3 which shows an example filtercomponent providing a mouthend with a recessed portion 10. Inconjunction with the component 7 can provide a mouth filter portion 3with the recess 10 in it for use in the article. This structure providesan aesthetically pleasing construction that can contribute to productstrength by employment of the layered overwrap 4. It also allows thepossibility of provision of a shorter filter component 7 which canreduce total pressure drop. With such an example the filter portion 7will generally be 6 mm in length or longer to ensure it retains materialin the tobacco portion 2 that still provides appropriate structuralintegrity whilst controlling pressure drop and compressibility for theoverall article.

FIGS. 7 and 8 depict usage of the current invention with an electroniccigarette as the aerosol-generating device. The device utilises abattery power source 14 to heat a resistive wire 17 in order tovolatilise an e-liquid from reservoir 16, the liquid is typicallynicotine-free. The article of the invention 19 is inserted into theelectronic-cigarette device at point 18. The first aerosol produced byresistive wire 17 passes through article 19 and is modified to producethe inhalable aerosol 20. The modification to the first aerosol includesthe addition of nicotine and other flavourants from the presentinvention. The modification can also include the removal of undesirablechemical components via attenuants and the removal of undesirableaerosol and other particles from the aerosol.

In an alternative embodiment, the first aerosol additionally containschemicals to assist the incorporation of desirable chemicals from thetobacco derived portion 2 into the aerosol. Preferably the first aerosolcontains volatile acids which act to incorporate freebase nicotine fromthe tobacco derived portion 2 and thereby enhance the amount of nicotinein the inhaled aerosol. Suitable volatile acids include ascorbic,pyruvic acid and levulinic acid.

FIG. 10 shows an alternative use of the current invention, whereby thecurrent invention is inserted into a device with power source 14 whichuses a heat-source 23 to directly heat the tobacco portion 2. The actionof the heat from the associated device releases volatile components fromthe invention which form the inhalable aerosol. Heat source 23 includesone of electrically driven or chemical reaction driven heating means.Electrically driven options include metallic heating elements, resistivewire, thin film heaters, ceramics heaters and combinations thereof inconjunction with a battery or cell. Alternatively, an electricallydriven heat-source 23 can rely upon induction, where an alternatingelectromagnetic field is produced which in turn generates heat in asuitably placed susceptor element 24. The efficiency of induction isimproved when the susceptor element 24 is in close proximity to thematerial to be heated, therefore the susceptor element 24 is best placedwithin the tobacco derived material or as part of the overwrap incontact with the tobacco derived portion. In the case of inductionheating the power source and circuitry may be configured to operate at ahigh frequency. Preferably, the power source and circuitry may beconfigured to operate at a frequency of between approximately 80 kHz and500 kHz, preferably approximately 150 kHz and 250 kHz, more preferablyapproximately 200 kHz, and the assembly may be arranged to operate inuse with a fluctuating electromagnetic field having a magnetic fluxdensity of between approximately 0.5 Tesla (T) and approximately 2.0 Tat the point of highest concentration. Whilst the induction coil maycomprise any suitable material, typically the induction coil maycomprise a Litz wire or a Litz cable. The susceptor may comprise one ormore, but not limited, of aluminium, iron, nickel, stainless steel andalloys thereof, e.g. nickel chromium. With the application of anelectromagnetic field in its vicinity, the susceptor may generate heatdue to eddy currents and magnetic hysteresis losses resulting in aconversion of energy from electromagnetic to heat.

Chemical reaction driven heat sources include combustion, oxidation,redox and other exothermic reactions.

Humectants are additives that act to retain water within a matrix andinclude polyols such as propylene glycol, glycerol, PEGs of variousmolecular weights, sugar alcohols such as sorbitol and combinationsthereof. Within the present invention volatilised humectants alsofunction to produce aerosol droplets. Preferably the humectant is amixture of propylene glycol and glycerol.

pH modifying agents include acids, bases and buffers which can be usedto alter the ionisation state of chemicals within the tobacco derivedportion thereby modifying their volatility. Notably free base nicotinewhich predominates at alkaline pH is significantly more volatile thannicotine salts which predominate at acidic pH. In a preferred embodimentsufficient basic agents are added to the tobacco derived portion toachieve an overall pH>7 rendering more nicotine available to bevolatilised into the inhalable aerosol. More preferably the overall pHis >8. Suitable basic agents include metal carbonates, metal hydrogencarbonates, metal hydroxides and ammonium salts.

In one embodiment of the present invention the tobacco derived portion 2is generated by providing a blend of tobacco grades comprising fluecured and air-cured tobaccos with a chemical composition in accordanceto Gothiatek® Standard, namely tobacco-specific nitrosamine (NNN+NNK)content of <1 mg/kg and benzo[a]pyrene content of <1.25 ug/kg. Onceblended, the tobacco is reduced in size by first shredding and thengrinding to pass through a No. 18 Mesh giving a particle size of =<1 mm.To the ground tobacco is added 50% equivalent mass of deionised water;2% equivalent mass of flavourant—a 50:50 mix of menthol and mint oils;0.375% equivalent mass pH modifying agent—sodium hydroxide. Theresultant tobacco paste is passed through a Coperion extruder withbarrel temperature 250° C. and pressure 4 atm linked to a pelletizer toproduce a shaped material of particle size approximately 1.5 mmdiameter. The tobacco derived particles are then dried under vacuum to<10% moisture. The dried tobacco particles are then sieved to produce afraction in the range 0.2 mm˜1.25 mm. The mouth end and distal endfilter portions 1,3 are manufactured using a Hauni filter rod makingmachine. Filter portions 1,3 are made from cellulose acetate tow 6Y17using 10.1 mg of tow per mm of filter length; plasticised with 12%weight/weight triacetin; 26 gsm, 2000 CU plugwrap affixed with PVA glue.Final filter portion dimensions are 8 mm diameter and 6 mm length. Theassembly of the non-combustible tobacco article is carried out on aMolins cavity filter machine using a paper overwrap PPW 35 by SWM with a0.1% coating of AKD on the inner surface. The construction of thearticle is 6 mm filter portion, 17 mm cavity with 250 mg tobacco-derivedmaterial, 6 mm filter portion affixed with PVA glue. This generates afinal article with a total pressure drop of 40-65 mm water column andcompressibility factor of ˜3% in the longitudinal axis.

With the present invention, by controlling the compressibility of thearticle it is possible to provide a device which is easy for a user tohandle and remove from a vapour generating device without deformation ordamage even though the generation of vapour during use will potentiallydeteriorate the mechanical properties of the article. By optionallycontrolling draw pressure it is possible to ensure a pressure drop thata user is comfortable in creating the draw pressure when receivingvapour. In addition, the invention ensures that an article to hold anappropriate of vapour generating material can be provided in an articlewhich is aesthetically pleasing and simple and straightforward tomanufacture.

1. A non-combustible tobacco article for use in conjunction with a heat source to produce an inhalable aerosol, the article comprising at least one tobacco derived portion, at least one distal filter portion and at least one mouth-end filter portion held together along a longitudinal axis in an overwrap; the complete article having a compressibility factor in the longitudinal axis of <10%, the compressibility factor being measured in the longitudinal axis by application of a force of 10 Newtons at ends of the article and measuring deflection distance as a percentage of total length of the article.
 2. The tobacco article according to claim 1 arranged to have a total pressure drop <120 mm water column across the article in the longitudinal axis.
 3. The tobacco article according to claim 1 arranged such that in use the article modifies a first aerosol produced by the heat source to produce the inhalable aerosol.
 4. The tobacco article according to claim 1 arranged such that in use the article provides volatile components to the inhalable aerosol upon action of the heat source.
 5. The tobacco article according to claim 1 further comprising induction elements dispersed within the at least one tobacco derived portion such that, in use, electromagnetic energy can be applied to the induction elements to generate heat.
 6. The tobacco article according to claim 1 where the at least one tobacco derived portion contains at least one from the group of a flavourant, a humectant and a pH modifying agent.
 7. The tobacco article according to claim 1 where the at least one tobacco derived portion contains a flavourant, a humectant and a pH modifying agent.
 8. The tobacco article according to claim 1 where the overwrap includes at least one transparent region.
 9. The tobacco article according to claim 1 where the overwrap is arranged to resist absorbing volatile and aerosol components in the at least one tobacco derived portion such that the total weight gain by absorption after use is <10% of the original overwrap weight.
 10. The tobacco article according to claim 1 where the overwrap is wound in a helical direction relative to the longitudinal axis of the article.
 11. The tobacco article according to claim 1 where the at least one mouth-end filter portion comprises at least two distinct regions abutted together.
 12. The tobacco article according to claim 1 where the at least one mouth-end filter portion and the at least one distal filter portion separately or combined contain at least one from the group of an aesthetic element, a flavourant and an attenuant.
 13. The tobacco article according to claim 1 where the at least one mouth-end filter portion and the at least one distal filter portion separately or combined contain a flavourant and an aesthetic element.
 14. The tobacco article according to claim 1 where the at least one mouth-end filter portion and the at least one distal filter portion separately or combined contain an attenuant, a flavourant and an aesthetic element.
 15. The tobacco article according to claim 1 where at least one of the at least one mouth-end filter portion and the at least one distal filter portion contains at least one airflow channel in the longitudinal axis.
 16. A process of manufacturing a tobacco article, the method comprising the steps of: forming at least one distal filter portion and at least one mouth-end filter portion; arranging said filter portions within an overwrap in such a manner to form a cavity between the at least one distal filter portion and the at least one mouth-end filter portion; filling the cavity with tobacco derived material; and closing the overwrap material to form an integral unit. 